PROJECT SUMMARY In 2015 and 2017, the US Departments of Education and Health and Human Services issued a joint policy statement highlighting ?all young children with disabilities should have access to inclusive high-quality early childhood programs.? Early childhood (EC) educators must be able to meet diverse educational needs, however the complexity of many current interventions for young children with autism spectrum disorder (ASD) limits their feasibility. Active engagement (AE) has been designated as a key component of effective programming for students with ASD (Iovannone et al., 2003; Ruble & Robson, 2007). Relatedly, social emotional competencies in preschool-aged children, those closely related to impairments implicated in ASD, predict academic achievement across the general population within K-12 (Durlak, Weissberg, Dymnick, Taylor, & Schellinger, 2011; Jones, Greenberg, & Crowley, 2015). Social Emotional Engagement-Knowledge and Skills (SEE-KS) is an evidence-informed Tier 1 professional development (PD) intervention that originated in Georgia and Wisconsin as K-12 administrators sought a robust approach for increasing teachers? capacities to support AE and provide equitable access to the curriculum for all learners. SEE-KS is currently implemented in school districts across five states. In Georgia alone, SEE-KS implementation has increased from three school districts in 2013-14 to 23 school districts in 2018-19. SEE-KS draws upon research on social emotional learning (SEL) and principles of Universal Design for Learning (UDL), and uses coaching to increase opportunities for AE. The current research will adapt and field test SEE-KS for use as an ASD-specific intervention in EC settings. We will develop (1) a 2-hour self-paced online introduction to SEE-KS for EC professionals, and (2) a coaching model that is acceptable and feasible across a range of EC settings. In Year 1, we will use an innovative implementation method (Dynamic Adaptation Process, DAP) to account for the multi-level context of service delivery and engage stakeholders throughout the adaptation process. In Year 2, EC educators (N=30) will participate in field testing and data collection aimed at evaluating the acceptability and feasibility of the PD package. EC educators are eligible to participate if their classroom includes a student with ASD whose parents provide informed consent to participate in this research. Participant teachers will complete questionnaire measures before and after the training. Further, classroom videos will be recorded and coded for implementation fidelity and student AE. Teacher participants will receive three coaching sessions over a period of three months. SEE-KS coaching will focus on increasing AE of the target student with ASD across teacher-identified activities and routines. For each participant teacher, we will collect classroom video of targeted activities before, following, and three months after coaching to assess change in child AE. Feasible and acceptable PD interventions for EC settings that effectively increase AE in students with ASD are critical to ensure that all children have access to evidence-based early intervention.